[Paroxysmal tachycardia with long QRS (left branch block type) in a female patient with accessory nodo-ventricular pathway. Role of the anomalous pathway in the electrogenesis of the arrhythmia]. / Tachicardia parossistica a QRS larghi (tipo blocco di branca sinistra) in una paziente con via accessoria nodo-ventricolare. Ruolo della via anomala nella elettrogenesi dell'aritmia.

The authors report a case of paroxysmal tachycardia with widened QRS (left bundle branch block morphology), where the electrophysiologic investigation shows an accessory nodo-ventricular pathway and suggests its involvement, as descendent (anterograde) pathway in a circular movement, the ascendant (retrograde) limb of which is the nodo-hisian pathway.

[Ventricular fibrillation induced by transesophageal stimulation performed for the treatment of atrial flutter]. / Fibrillazione ventricolare indotta dalla stimolazione transesofagea attuata per il trattamento di un flutter atriale.

The authors describe a case of ventricular fibrillation occasionally induced by high rate transesophageal pacing, performed to treat an atrial flutter. They conclude that, although this technique is generally safe and well tolerated, it must be performed exclusively where an intensive care can be provided.

[Plasma levels of anti-arrhythmic drugs and clinical effectiveness in the treatment of ventricular arrhythmias]. / Livelli plasmatici dei farmaci antiaritmici ed efficacia clinica nel trattamento delle aritmie ventricolari.

In spite of the ratio between plasmatic concentration and antiarrhythmic effects of a drug many factors can be influenced by many factors, the plasma level monitoring plays an important clinical role. The efficacy of the antiarrhythmic therapy should be evaluated not only by means of ECG-Holter monitoring and/or electrophysiological study but also by the means of determination of plasmatic and tissular concentration of a drug and metabolites. This latter is indispensable in the evaluation of new antiarrhythmic drugs and of a dose/effect relationship during acute and chronic therapy.

[Hemodynamic aspects of torsade de pointes: echocardiographic study of a case]. / Aspetti emodinamici della torsione di punta: studio ecocardiografico di un caso.

In a patient with complete heart block complicated by "Torsade de point" (T.D.P.) we were able to record an M-mode echocardiogram during an attack of this peculiar ventricular tachyarrhythmia. The aortic valve opening was inconstant, incomplete and unequal during the T.D.P. (13 sec.), although the rate of the tachyarrhythmia was almost constant. On the other hand, during a subsequent ventricular pacing at a comparable rate like, the aortic valve opening was constant and complete. On the basis of these observations we conclude that the reduction of stroke volume, observed in T.D.P., is mainly due to mechanical failure as a result of partial desynchronization of the ventricular activation, as in ventricular fibrillation in which, however, the desynchronization is complete.

[Multiform ventricular tachycardias and Torsades de Pointe]. / Tachicardie ventricolari polimorfe e torsioni di punta.

The term Torsade de Pointe (T.d.P.) was first introduced by Dessertenne (1966) to designate an unusual ventricular tachyarrhythmia characterized by paroxysms of V.T. at rates typically greater than 200 beats/m, in which the QRS morphology shows alternating polarity in a modulating pattern, so that the complexes appear to be twisting around the baseline. This arrhythmia, triggered by E.V.B. falling in the vulnerable period of a previous beat, occurs in the setting of a prolonged Q-T interval, is generally self-limiting and, occasionally, degenerates into V.F. Similar morphologic features may be observed in patients with a normal Q-T interval. The duration of Q-T interval has important therapeutic implications. The arrhythmia occurring in the setting of a prolonged Q-T requires strict avoidance of all drugs that may potentially further delay repolarization (including class I antiarrhythmic agents), whereas that occurring with a normal Q-T interval usually responds to conventional therapy (including administration of class I antiarrhythmic agents). Thus, it seems reasonable to reserve the term T.d.P. exclusively to the forms with prolonged Q-T interval and to define those with normal Q-T interval with the name of multiform (or polimorphous) ventricular tachycardia (M.V.T.). In this paper the Authors discuss the most important electrocardiographic, clinical, aetiological, electrogenetic features of both the T.d.P. and M.V.T., on the basis of their own experience.

[Drug treatment of a trial fibrillation in patients with Wolff-Parkinson-White syndrome]. / Esperienze di trattamento farmacologico della fibrillazione atriale in pazienti con sindrome di Wolff - Parkinson - White.

In 10 patients with ventricular preexcitation (Kent bundle), in whom atrial fibrillation (A.F.) was present, the effect of some common antiarrhythmic drugs on the conduction through the anomalous pathway, and on the ventricular rate was estimated. Procainamide caused transient complete block in the accessory pathway (disappearance of the aberrant QRS) and marked reduction of the average ventricular rate in all instances. Lidocaine caused incomplete block in the accessory pathway (reduction of the number of the aberrant QRS) and significant reduction of the average ventricular rate in all tested subjects. Amiodarone slowed the ventricular rate (increase of the average and minimum R-R intervals between wide QRS complexes) in two patients, but it did not block the anomalous pathway (all QRS complexes remained aberrant); whereas in 1 patient the ventricular rate became faster and regular and the patient had syncope, while the QRS remained always aberrant. This response was probably due to the change of A.F. into atrial flutter with atrio-ventricular conduction through the anomalous pathway only. Digitalis increased the average ventricular rate and shortened the minimum R-R interval between aberrant QRS complexes 3 out of 3 times. On the basis of our experience and of the data in the literature, we conclude that, in the management of A.F. in patients with W.P.W. syndrome:--the most effective drugs are those of the 1st group of Singh and Hauswirth classification (especially Procainamide and Ajmaline);--Lidocaine is less effective, but not ineffective and its utilization may be recommended whenever the previous drugs may be hazardous;--Amiodarone, although capable of modifying the electrophysiologic properties both of the anomalous pathway and of the A-V node, seems to be less reliable;--the drugs which influence only the A-V node (Verapamil, beta-Blockers, etc.) are quite ineffective;--finally, the Digitalis is not suitable because this drug increases the ventricular rate by decreasing the effective refractory period (ERP) of the anomalous pathway.

[Electrophysiologic demonstration of dual atrioventricular nodal pathways and final common pathway in a case of A-V nodal paroxysmal tachycardia. Considerations on the functional complexity of the A-V node (author's transl)]. / Dimostrazione elettrofisiologica di doppia via nodale e di una via finale comune in un caso di tachicardia parossistica da rientro nel nodo A-V.

The AA. studied the A-V nodal conduction using the technique of induced PAB in a patient with A-V reentrant paroxysmal tachycardia. They observed that the conduction through the A-V node failed when coupling intervals A1-A2 were between 280 and 260 msec and, after, recovered, with consistent slackening, when A1-A2 intervals were shortened, until the atrial ERP was reached. This uncommon response indicates the functional complexity of the A-V node and, particularly, suggests the presence of a final common pathway distal to the fast and slow A-V pathways, that are the anatomic-functional basis of the reentry circuit in A-V nodal paroxismal tachycardia.